Access Type
Open Access Dissertation
Date of Award
January 2012
Degree Type
Dissertation
Degree Name
Ph.D.
Department
Biological Sciences
First Advisor
D Carl Freeman
Second Advisor
Daniel M. Kashian
Abstract
Although dioecious species are rare in nature, the sexual system appears in a diverse number of families and across all life forms and global locations. We looked at the population dynamics of natural populations to determine why many dioecious populations display biased sex ratios. We also looked at the role incestuous matings, seed and pollen dispersal patterns, and compensation play in the evolution of this sexual system using two theoretical models we developed. Finally, we studied aspen populations in the Midwest to determine how climate variables affect growth and decline. We found many dioecious species display male biased ratios and that life form and dispersal agents are good indicators. Our theoretical models imply that incest and dispersal specialization of unisexual individuals facilitate invasion, but through the interaction of specialization, incest, and compensation, unisexual invasion occurs much more consistently and under less stringent conditions then previously modeled. Finally, we found that declining aspen stands were much less responsive to climate variables than healthy stands and that a number of stand characteristics could be used to discriminate between responsive and non-responsive stands.
Recommended Citation
Sinclair, Jordan P., "Dioecious Plants: Evolution And Sex Ratio And Asepen Decline" (2012). Wayne State University Dissertations. 620.
https://digitalcommons.wayne.edu/oa_dissertations/620